Urban Growth and Geohazards Constraints as Drivers of New City Creation: The Case of Ali Mendjeli and Constantine, Algeria

Constantine is one of Algeria’s major metropolitan centers and is recurrently affected by landslides due to its complex geomorphological context, characterized by steep slopes, deeply incised valleys, and mechanically weak lithological formations. Over recent decades, rapid population growth, land scarcity, and the expansion of informal settlements have significantly intensified exposure to slope instability. Previous studies have largely focused on hazard identification, susceptibility mapping, and engineering mitigation measures, while limited attention has been given to how these risks intersect with social practices, residential choices, and everyday urban life. In response to increasing landslide risk and related urban challenges in Constantine, the new city of Ali Mendjeli was developed as a large-scale resettlement project intended to reduce exposure by relocating vulnerable populations. However, despite the technical rationale behind this intervention, a noticeable proportion of relocated households have gradually returned to risk-prone areas within the historic city. This study addresses this gap by integrating landslide susceptibility assessment with a social-geographical analysis of resettlement outcomes. A landslide susceptibility map for Constantine was produced using Geographic Information Systems, integrating topographic, geological, hydrological, and anthropogenic conditioning factors through an Analytic Hierarchy Process (AHP). This spatial analysis was complemented by qualitative methods, including the review of planning documents, field observations, and semi-structured interviews to examine perceptions of risk, place attachment, and daily spatial practices. The results show that urban saturation and informal housing in Constantine strongly influenced the decision to create Ali Mendjeli as a resettlement site. However, the relocation process was implemented with a primary focus on quantitative housing provision, without adequate consideration of social networks, social attachment to the historic city center, and everyday spatial practices. The regrouping of households by original neighborhoods, combined with limited urban connectivity and weak functional diversity, contributed to early social fragmentation. Consequently, Ali Mendjeli evolved as a socially fragile urban space where pre-existing vulnerabilities were reproduced rather than mitigated, encouraging some residents to return to risk-prone areas. These findings demonstrate the limitations of purely technocratic, hazard-driven resettlement strategies and highlight the need for integrated approaches that align geohazard management with social sustainability, urban cohesion, and long-term resilience.

 

Keywords: Landslide susceptibility, Urban resettlement, Informal housing, Urban resilience, Social Geography, Urban attachment.